The generation of analytic data for monitoring network sessions is useful both for visibility and troubleshooting. One piece of data that is often useful for such troubleshooting is the generation of a round trip time (RTT) between a network device and the endpoints consisting of a client endpoint and a server endpoint. One way to generate the time is to monitor the Transmission Control Protocol (TCP) connection between the network device and the endpoint, but if there is a network intermediary between the network device and either endpoint, measuring RTT based on TCP connection may not be accurate.